Myke wrote


>No.  It's because RA4 is actually an Open Collector Output, which means that
>it can only pull a bus (as opposed to a line) to ground.

>Think of it as a switch pulling a signal to ground.

>If you want to use it as a driver, put a pull-up on it and it will work like
>the other ports.

This is not exactly true as this port cannot source any current to a
device, such as driving a led. It can only sink current and thus works as
an inverting driver, as you would have to take the output low to light
the LED from a positive rail.

Tony


Just when I thought I knew it all,
I learned that I didn't.